#include<stdio.h>

int main (void)
{
	int m,n,i;
	double sum;
	
	printf("Enter m,n:");
	scanf("%d %d",&m,&n);
	
	for (i=m;i<=n;i++)
	{
		sum = sum + m*m+1.0/m;
		m = m + 1;
	}
	
	
	printf("%.6f",sum);
	
	
	
	return 0;
}
